2-56. BACKWASH TIMER.
a. General. The backwash timer is used to automatically control the backwash operation. It is mounted on a
bracket that is attached to the multimedia filter. This paragraph describes removal, cleaning, inspection, repair,
and installation of the backwash timer.
b. Removal. (Figure 2-60)
ELECTRICAL HIGH VOLTAGE
Electricity can cause serious injury or death. Be certain that all
power is removed before performing maintenance on electrical
Disconnect control box connector (1) from backwash timer power connector (2).
Remove backwash timer power cable (7) from backwash timer in accordance with paragraph 2-64.
Improper connection of pressure hoses to backwash timer will
damage the timer. Label all hoses before disconnecting them
and check carefully before reconnecting them.
All water line connections for the backwash timer must be
properly tagged before disconnection.
Unscrew eleven coupling nuts (3) and disconnect eleven associated hoses from backwash timer.
Remove two screws (4) and two lockwashers (5) from backwash timer (6) and mounting bracket (8).
Open timer box cover and remove bracket (8).
Remove backwash timer (6).
(1) Inspect backwash timer for damage.
(2) Inspect power cable for cracked insulation, bare wires, and missing or broken terminal lugs.
(3) Inspect pressure hoses for cracks.
(4) Inspect mounting screws, coupling nuts, tees, and elbows for stripped threads.
d. Repair or Replace.
(1) Replace damaged or worn control box cable assembly.
(2) Replace damaged or worn power cable assembly.
(3) Replace damaged or worn hoses or tube assemblies.
(4) Replace all damaged nuts, bolts, screws, and washers.
(5) Replace damaged or unserviceable pipe fittings.
(6) Replace damaged or unserviceable backwash timer assembly.
(7) Send all damaged or unserviceable component assemblies to Direct Support Maintenance for repair.
*U.S. GOVERNMENT PRINTING OFFICE: 1993- 755-028/80268
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